Would you notice 40 - 50g difference? Remind me when the Covid restrictions are lifted and I might set up a blind test by adding weight to the rim tape. I doubt I'd notice, maybe others will. I did run latex tubes in an Audax bike for a while, I didn't notice the weight difference or the supposed improvement in rolling resistance. I'm not saying there is none, just that it wasn't of a magnitude that I'd notice, and keeping them at an acceptable pressure was a real pain.
I use latex tubes on 3 bikes (700C x 28, 26" x 1.6" and 26" x 1.95"). Compared to standard butyl:
Puncture protection - don't believe there is much difference, although increased puncture resistance with latex is claimed by some manufacturers.
Weight difference - don't notice. Never bothered to check the weights.
Rolling resistance - not really noticeable for me in 700C, but I think I notice an improvement in 26" x 1.95".
Can't say for 26" x 1.6" because I haven't tried butyl tubes on that size of tyre.
Comfort - better in 700C and 26" x 1.95" sizes (at same pressure), so I believe that would be the same in 26" x 1.6".
All the above is opinion, I have no figures to back this up. Although the test below seems to confirm my belief insofar as wide tyres and lower rolling resistance is concerned:
https://www.bicyclerollingresistance.com/specials/tubeless-latex-butyl-tubesThe same site also did comparative tests of Tubolito polymer inner tubes:
https://www.bicyclerollingresistance.com/specials/tubolito#tubolito-mtb My 3 bikes with latex are my heavy tourer and my fast day bikes, which generally get used for longish rides where the (perceived or imagined) extra comfort outweighs the hassle of checking tyre pressure before each ride. I don't bother with latex on my utility bikes, these have butyl tubes.
I don't want to try plastic tubes, as I reckon field repairs will be difficult, I don't find latex tubes difficult to patch. And I will continue to avoid tubeless if possible, because fitting and repair seems more complicated, even if there may be less punctures. I have tried lightweight versions of butyl tubes, and had a few problems with tube failure, this is also more frequent with latex, which perishes after a few years.
Latex is more hassle than butyl, but it is hassle I am used to.